VXI Corporation VXI-203515 Cc Pro 4021P Dc (Bulk) (VXI Corporation VXI-203515) Wideband audio for natural, easy-to-understand sound. Advanced noise canceling improves communication by cutting nearly 90% of background noise. UC-ready to fit right into your Unified Communications strategy. Compatible with VXi, Plantronics or GN Netcom/Jabra amplifiers and direct-connect cords.